From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80972][MODERATE REGULAR] ALSA: aloop: Check card index validity at probe Date: Fri, 11 Sep 2026 17:40:45 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80972 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 1 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: c589aeaadfde1cfedb5c6f0a3c782807282126d9 List-Id: CVE: CVE-2026-80972 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: ALSA: aloop: Check card index validity at probe Commit: c589aeaadfde1cfedb5c6f0a3c782807282126d9 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c589aeaadfde1cfedb5c6f0a3c782807282126d9 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80972 Analysis date: Fri, 11 Sep 2026 17:40:45 -0400 ActionableScore: 1 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80972 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80972 The original announcement does not normally provide a security severity estimate, CVSS assessment, or enough information to determine whether the reported kernel bug represents a practically relevant security issue. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. It combines an autonomous classifier with LLM-assisted technical analysis and a separate ActionableScore mechanism. The purpose of this report is to prioritize Linux kernel CVEs before manual review, identify cases that require prompt investigation, and support automatic closure of issues that are unlikely to have meaningful security impact. Published priority for this report: MODERATE REGULAR Manual review required: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-80972 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-80972 CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H';CWE-129;CWE-125;*CWE-20;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '6.1';DESCR 'An OOB access in the ALSA aloop probe path can occur because the driver trusts devptr id as a valid card index before reading per card parameter arrays. A manually bound platform device can provide an invalid id such as none, causing out of range reads of parameters used to create and configure the sound card. For the CVSS the PR:L is used for the paranoid case because a reduced capability root, a service account, or delegated sysfs driver binding can be enough in some deployments, while typical systems require administrator privileges. The issue is local and is not network reachable. Impact is primarily denial of service via kernel crash, with limited confidentiality impact considered possible due to kernel OOB reads but no clear arbitrary write or privilege escalation primitive.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1) YES OOB SIMPLEFIX HARDWARE LINUS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=YES NamespaceScopedPrivilege=NO ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 1 * Conservative score: 1 * Raw paranoid score: 1 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate**:: No floor or cap changed the score. 2. Signal breakdown Positive signals: * +1 Weak or indirect corruption candidate: `loopback_probe()` uses `devptr->id` as an array index before validating it, allowing OOB reads from per-card parameter arrays such as `index[]` and `id[]`. Negative signals: * -1 Host-admin-equivalent reachability constraint: the described trigger is manual driver binding through sysfs, which is normally a host administrator controlled operation. Important non-awarded signals: * RealUAF not awarded: no stale lifetime use, double release, or post-free object use is shown. * Strong corruption not awarded: no OOB write, arbitrary write, controlled reclaim, callback control, or type confusion is established. * Confidentiality not awarded: the OOB read is internal and no user-visible disclosure path is established. * Integrity not awarded: no unauthorized modification of kernel state or protected object is established. * Extra Availability not awarded: possible crash/OOB failure is not enough to add a separate availability point beyond the weak corruption signal in this scoring. * Local unprivileged trigger not awarded: below-host-admin reachability is not established. * NamespaceScopedPrivilege not awarded: sysfs driver binding is not shown to be namespace-scoped. * Remote reachability not awarded: this is not network-triggerable. 3. Reachability analysis The trigger described by the commit is manual binding of the aloop platform device through the sysfs driver interface. That path normally requires host administrator authority because writing to driver bind or unbind files in sysfs is a host-global device-management operation. No evidence shows that an ordinary local user can create or bind the relevant platform device, and no evidence shows that the complete trigger works inside an attacker-created namespace. There is no network path. There is no special external hardware requirement beyond the ALSA loopback driver being present and the relevant device-binding operation being available. No race or difficult timing condition is involved. 4. Primitive and severity interpretation The exact primitive is an unchecked card index used for OOB array access during `loopback_probe()`. This is not an active structured UAF and not fixed stale storage. It is an invalid index / OOB read of kernel parameter arrays that may feed invalid values into sound card initialization. PrimitiveClass is CLASS_C because the demonstrated behavior is an invalid-state/OOB-access condition with likely crash or misconfiguration consequences, but no independently useful corruption primitive is established. The demonstrated consequence is local DoS or failed initialization. A stronger consequence such as information disclosure or privilege escalation is speculative because no disclosure sink, write primitive, controlled target, or lifetime corruption is visible. ImportantCandidate is NO because this is not Class A and does not present unresolved Class B lifetime or ownership leverage. AutoDowngradeAllowed is YES because the issue is host-admin-gated, crash/misconfiguration oriented, and lacks UAF, repeated refcount mutation, authorization bypass, or controlled corruption. Likely operational severity is ordinary Moderate / Low-like. 5. One-sentence report phrase An unchecked card index in the ALSA aloop probe path can cause OOB access to per-card parameter arrays when the device is manually bound through sysfs, with impact primarily limited to local denial of service or invalid device initialization. 6. Manual review recommendation MANUAL CHECK RECOMMENDED Reason: this is kernel OOB access and should be sanity-checked for any downstream disclosure or write side effects, but current evidence supports host-admin-gated crash/misconfiguration impact only. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ALSA: aloop: Check card index validity at probe Commit: c589aeaadfde1cfedb5c6f0a3c782807282126d9 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c589aeaadfde1cfedb5c6f0a3c782807282126d9 Commit description: aloop driver blindly trusts that the given devptr->id value is within the proper card index range at probe. It's OK for the devices the driver itself creates at the module probe time, but if the device is bound manually via sysfs interface, this could be -1 as "none", and this leads to OOB access for index[] and other parameters. Add a sanity check for the card index and warn/correct it if it's a value out of the range. Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20260806153227.1460166-2-tiwai@suse.de Signed-off-by: Greg Kroah-Hartman Changed files: sound/drivers/aloop.c Diff excerpt: Not included in this email. See the upstream URL for the full patch. Full patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c589aeaadfde1cfedb5c6f0a3c782807282126d9 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80972 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80972 The original CVE announcement normally does not include a security-level estimate. In particular, it may not contain a CVSS assessment, an impact level, or enough information to determine whether the reported bug is a practically relevant security issue. One purpose of this parallel CVE list is to provide that missing technical and prioritization information. The original goal of the AL-KERNEL project was to prioritize Linux kernel CVE analysis automatically before manual review. The system can also help identify non-security issues that may be suitable for automatic closure. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. The first analysis stage combines an autonomous classifier with additional LLM-based analysis. The autonomous classifier runs locally on a CPU and is based on a backpropagation neural network. Together, these mechanisms produce a technical vulnerability description, identify likely weakness types, estimate CVSS severity, and provide input for ActionableScore. Two CVSS estimates are retained because incomplete kernel vulnerability information often permits more than one defensible interpretation: Conservative CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H The Best / paranoid CVSS score: 6.1 The conservative vector represents a lower-impact interpretation. The Best/paranoid vector intentionally represents a plausible upper-bound interpretation and should not automatically be treated as demonstrated real-world impact. CVSS may also need to be adjusted for a particular Linux deployment, because actual reachability, privileges, enabled kernel configuration, hardware, namespaces, exposed device nodes, and other environmental conditions can differ significantly between systems. A separate ActionableScore mechanism evaluates practical remediation urgency. Its analysis may include reachability, attack prerequisites, subsystem exposure, memory-corruption characteristics, denial-of-service reliability, and possible confidentiality, integrity, or privilege-escalation impact. Conservative ActionableScore: unknown Paranoid ActionableScore: 1 The final base severity is taken directly from the second tab-separated field of the AL-KERNEL classification result. ActionableScore does not replace or independently override that final AL-KERNEL decision, and if ActionableScore adjusted impact level of ALKERNEL, then you would see self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7. For an AL-KERNEL result of MODERATE, this report uses the following additional presentation split: ActionableScore below 5 -> MODERATE REGULAR ActionableScore 5 or more -> MODERATE 7.0 The distinction between MODERATE REGULAR and MODERATE 7.0 makes it possible to identify Moderate issues that should receive manual analysis and fixes before lower-priority MODERATE REGULAR issues. In many cases, MODERATE REGULAR fixes may wait for a later rebase or routine update. There is one override in which MODERATE REGULAR becomes MODERATE 7.0 even when the ActionableScore is below 5. When the AL-KERNEL result contains the KPANIC flag, a MODERATE result is always presented as MODERATE 7.0. The KPANIC flag selected with few regexps without usage of AI at all, so it helps to detect cases when Kernel Crash happens and similar (to filter False-Negative results from the LLM usage). KPANIC indicates that a reliable kernel crash, kernel panic, or similarly serious kernel availability impact was identified by the classification workflow. AL-KERNEL base severity for this report: MODERATE KPANIC detected for this report: NO Published priority for this report (same as in Subject): MODERATE REGULAR These results are intended to support engineering triage. They are machine-generated estimates, and cases marked for manual review should be validated by a human security engineer before final disposition. For more info read docs linked from here: https://kernelcve.org/ (and you can submit you own patch there to generate such a report for non-existant CVE-id yet). Note that in many cases this AI tool selects higher severity, than real is (means you can expect Importants instead of Moderate 7.0 or Moderates 7.0 instead of regular Moderates). If you see such cases, please use reply email interface to add additional manual analyses info to this particular CVE. And please, please, let me know when you see Lows instead of Importants or Important instead of Low (because particular for such cases I need to tune this AI tool to make it better for this one and next similar). My contact email for such notifications is alexanjelausa@gmail.com (and both send reply to CVE record itself too and see "reply" button below for howto reply).